Power-transmission chain



' 9 1927. Aug w. J. BELCHER POWER TRANSMISSION CHAIN Original Filed Feb. 15. 1921 3 Sheets-Sheet 1 7164A TTORNEY$'- I 1 638,3 8 9 1927' w. J. BELCHER 8 POWER TRANSMI SS ION CHAIN Original Filed Feb. 15. 1921 3 Shoots-Sheet 2 WVM fl A TTORNEYS Aug. 9 1927. 1,638,388'

w. .1 BELCHER POWER TRANSMISSION CHAIN 4 Original Filed Feb. 15, 1921 a Sheets-Sheet a Patented Aug. 9, 1927.

UNITED. STATES PATENT OFFICE.

WARREN J. BELCHER, or nan'rroan, conuncrrou'r, ASSIGNOR "r THEWHITNEY MFG. COMPANY, OF nna'rronn, CONNEGTIGUT, A oonronn'rron or comvnc'rrco'r.

rownn-rnausnrssron- CHAIN.

Original application filed February .15, 1921, Serial No. 445,057. Divided and this application filed January :28, 1924.

My invention relates broadly and, gener ally to new and useful improvements in power transmission chains. and more particularly to the type in which the chain is composed of links consi "Eng of toothed plates arranged with-overlapping ends connect-ed by transverse connecting means.

The object of the invention is to provide an improved chain in which the wear be tween theparts, and particularly that wear to which the transverse connecting means is subjected, will be reduced or prevented so as to prevent such lostmotion between the parts which would result in lengthening of the chain to an objectionable degree.

The invention consists in the improvements .to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

1 have fully and clearly illustrated my invention in the accompanying drawings to be taken as a part of this specification, and wherein:

Fig. 1 is a view in side elevation of a section of the chain embodying-my invention;

Fig. 2 is a top plan view of the construction shown in Fig. 1; Y

Fig. 8 is a section on the line 33 of Fig. 1;

Fig. 4 is a view in side elevation of one of the link members or plates shown in the previous figures;

F 1g. 5 is a diagrammatical view showing a method of determining the form and relation of certain contacting faces with connectin means forming part of the invention;

Figs. 6, 7 and 8 are views corresponding 'to- Figs, 1, 2 and 3 and showing another embodiment of my invention.

Referring to the drawings by characters of reference, 1 designates. a link member preferably in the form of a plate, including heads or end portions 2, 2 connected by an intermediate or arch portion 3, said heads having sprocket-engaging portions or members, preferably in the form of teeth 4, 4, havinginclined side faces t adapted to engage with the teeth of a driving or driven gear or sprocket'(not shown). The cha n is made up of a plurality of said plates orllnks arranged side by side in parallel planes, with the ends or heads 2, 2, thereof in overlapping relation, the ends being connected Serial No. 688944.

by transverse connecting means, to be described latcr, by which the chain Links are pirotally connected and the chain completed. The chain may be made up of a plurality of chain units A (see Figs. 2 and 3), each of which consists of said outer link plates 1, and inner or intermediate plates 1 all of which may be of the same construction as shown, for example, three of such units may be used as shown in Figs. 2 and 3, and four as shown in 6 and 7.

The overlapping heads 2, 2 of the links in each unit are each provided with alining apertures 5, preferably circular in form as shown in Figs. 1 and 4., which apertures re ceive transverse connecting means conncctr ing the link plates and permitting relative movement between the same. According to one embodiment of my invention, the connecting means comprises transverse c0nnecting pins 6, 7, extending through said alining apertures, said pins being held in the apertures in said inner and outer plates, respectively, and having contacting faces in rolling contact. i

The pins 6, 7 are arranged in movable contact with each other at their adjacent faces at a point approximating the center of the link apertures, that is, at the center of turning movement between the links, sai d faces being" formed of curves providing for relative contact between the parts, and reducing wear to aminimum, so that the diameters of the pins are not reduced so as to result in lost motion between the bearing faces of the pins and consequent lengthening of the chain in use.

I have discovered that a most efficient construction for providing a substantial nonwearing contact between the pins is afforded by forming said faces, respectively, on ogee curves, so arranged as to provide proper extent of surface contact when the chain is moving in a straight line, and to permit center being designed so as to permit the curves on the adjacent faces of therespective pins below the center to engage substantially throughout the length of the latter faces below the center when the chain is pulling straight, and also to provide a space between the adjacent faces above the center for relative movement of the pins when the chain is curved as when passing about a sprocket or gear. The necessary amount of space between the upper adjacent curves depends upon the number of teeth in the sprockets over which the chain is designed to travel, that is, the space may be narrower relatively when the chain is to travel over large or many toothed sprocket wheels, but must be wider when used on sprocket Wheels having less teeth or of a smaller diameter, for example, twelve teeth.

lVhcn the space is made wide enough to adapt the links to have the proper relative movement of the links upon the smallest sprocket wheel upon which the chain is adapted to be used, said space will obviously be correct for sprocket Wheels of larger sizes upon which the same chain might be used. For example, if the space were made wide enough to permit proper relative movement.

in passing over a 12-toothcd sprocket this space would be wide enough to provide the proper relative movement to permit the chain to flex properly when passing over larger sprockets, as the necessary extent of movement for the larger sprockets would fall within the limits of the space necessary to permit the chain to pass over a l2-toothed sprocket. In designing the curved faces on the pins between which the relative move ment takes place, it is desirable to avoid as much as possible the formation of an abrupt or sharp contact or projection at the center of the chain. It is apparent that when the chain is used upon a l2-toothed sprocket, in which the teeth are spaced 30 apart, that such space must be provided for relative movement between the pins as will permit the pins to swing about their center a distance of 30. It is also desirable to so design these curves that this space willbe afforded. but, as stated, abrupt contact points will be avoided. A preferred form of the curved faces may be determined in the following manner, reference being particularly made to Fig. 5 of the drawings, in which the outer circle C corresponds to the circumference of one of the bores or openings through the ends of the links, and also to the outer circumferential faces of the pins, said circle, for purposes of explanation, being divided into spaces of 2 and 5, in order to make clear the manner of designing the of the pins. The vertical diameter of the circle is shown by a line passing from zero to 180, on the scale, this line or diameter corresponding to a line drawn through the centers of the link apertures 5 at right angles to the length of the chain when traveling etween sprockets. If the pins could be designed so as to have no line contact whatever at their centers, it would be necessary to form the engaging faces on a. radius of a length equal to the radius of the circle, in which event, arcs struck through the zero point on the circumference and the center of the circle from the 60 point to the right of the zero point, and from a point 60 to the left from the lower end of the vertical diameter would be tangential to each other at the center of the circle, but it is clear that were the faces on both pins so formed, said faces would en gage throughout their length, and one pin could not turn relative to the other without the link aperture 5- In order to approximate as near as possible the ideal form of contact face, just described, and at the same time provide for relative motion between t is pins, I alter the relation of each member of the ogee curve on each pin, so that the proper contact will be provided when the chain is traveling between the sprockets, and the proper relative motion will be afforded when the chain is passing around a sprocket.

In order to do this, the upper convex face or curve of the ogee on the pin 7 is formed on an are having a radius equal in length to the radius of the circle forming the external surface of said pins or the circumference of the opening 5, and with this radius I strike an are from a point on the circumference of the circle 67 to the right from the upper end of the vertical diameter, which are will extend through the center of the circle at a point 7 from the vertical, as indicated by the line XY, Fig. 5. In asimilar manner I take a radius equal to the radius of the circle and strike an arc from a point on the circumference 52 to the right from the upper end of the vertical d ameter, and strike an are which will pass through the center of the circle and through the circumference of the latter at a point 7 to the left of the Zero point or the upper end of the vertical diameter, as shown by the line XZ, Fig. 5, I

whereby the curve of the concave face on the upper portion of the pin 6 is determined, the convex face on the pin 6 is determined by taking a center 67 to the left of the vertical diameter at the bottom of the circle and scribing an are passing through the center of the circle at a point on the circumference of the latter 7 to the left of the lower end of the vertical diameter. as shown by the line XZ. The concave face on the pin 7 is formed by taking a radius equal to the diameter of the circle, and from a point on the circle 52 to the left from the vertical scribing an are passing through the center of the circle at a point on the circumference of the latter 7 t0 the right from the lower end of the vertical diameter 0f the circle, as shown by the line X--Y.. It will thus be seen that the points at which the lines X-Z and X--Y pass through the circumference of the circle are spaced 15 apart, and the same is true at the point at which the lines XZ and XrY pass through the circumference of the circle, the total circumferential distance between said points being 80, i. e., the distance required for rela- Y and KY. In arranging the pins in the completed chain, it is preferable to so arrange the line along which the faces of the curves XZ and KY meet, that when the chain is pulling straightthe line along which these curves meet will be located as near as possible on a line perpendicular to the length of the chain, and for this" purpose it is desirable to have the outer ends of these faces, or the line upon which these faces meet when the chain is pulling straight terminate, for example, 10 to the left of the vertical diameter of-the circle, in which event, a line forming a continuation of the outer face XZ would terminate at a pointon the circumference 5 to the left from the vertical, as indicated by the line X--Z and the face XY, if continued, would extend through a point on the circumference 25 to the right from'the vertical diameter of the circle, as indicated by line XY In Figs. 6, 7 and 8 is shown another embodiment of the same invention, in which the novel contacting faces at the joint instead of being made on two coacting transverse members or pins, are made, respectively, on a wall of the opening in one of the links, and a pin or transverse member carried by the end of the overlapping link. As shown in these figures, one of the links is provided with openings 5 corresponding to the openings 5, heretofore described, and each having a circular wall 5 arranged toward the end of the link, and an inner wall 5 formed, on an ogee curve, for 8X' ample, like the curve XZ and XZ (Fig. 5). This link may be the pin-carrying link. The overlapping link is provided,

with openings 5 similar to the openings 5*, heretofore described, but arranged reversely, that is, with the circular walls innermost, and the ogee walls toward the ends of the link, these latter walls also having the same curvature as the wall 5. This may be what is known as the pivoting link. -When the chain links are assembled, the opening 5*, for example, in the rear of its link, is arranged in alineme'nt'with the opening 5 in the forward end of the overlapping link, and the rear opening in the latter will be arranged in alinement with the forward opening in the next following pin link. The links are thensecured together by a transverse member or pin 7, such as heretofore described, with the curved rear face thereof toward the curved walls of the alining openings 5 and 5, and with the concave-convex face of the pin opposed to the ogee curved I faces in said alining openings 5*, 5 after which the pin may be secured in place against endwise movement, in any suitable manner- It will be understood that in this form the fixed curved faces carried by the links, and the curved faces on the connecting member are formed in the same manner as heretofore described, particularlywith reference to Fig. 5. It will also be understood that the ogee faces on the walls of said openings and said connecting member are disposed-relative to the center so as to give the proper swinging movement between the links in passing about a sprocket, the curve of the pin and the curve of the opening in which it is seated conforming to the opening in the link and in which the pin' turns conforming to the curve X'Z I ZZ This application-is a division of my appli cation Serial No. M5957, filed February 15, 1921.

Iclaim: I

l. A,transmission, chain having a pluraliity of overlapping links with registering open ngs having reversely curved walls and a single pin passing through the registering openings to form a rolling joint with said walls between the adjacent sets of links.

2. A transmission chain comprising a plurality of overlapping links with registering openings in the overlapping ends, said openings having a reversely curved wall, a single pin passing through said openings and having a reversely curved wall, and a clearance space between said pin and the walls of the openings in certain of the links whereby a rolling joint is formed be tween the links of adjacent pitches.

3. A transmission chain comprising a plurality of overlapping link platesi having alining openings, a single transverse connecting member passing through the alining openings, said link plates having c0n veX and concave surfaces on the walls around said openings cooperating with said ing openings in the overlapped ends of the links, said pin and the walls of the openings each having oppositely curved bearing surfaces in rolling engagement to form joints between the adjacent sets of links of the chain.

5. A transmission chain comprising link plates having overlapping ends with alining openings at the joints, a connecting member at each joint extending through said openings and having reversely curved surfaces, cooperating reversed curved surfaces 011 the links, said surfaces being in contact throughout a substantial portion of their area below the center line when the chain is running straight.

6. In a chain ofthe silentlink type, a joint bet-ween adjacent sets of links comprising a. single pin having an oblong cross section with reversely curved sides, said pin being thinner at its edges than the middle, the link openings having reversely curved walls engagin said pin and forming rolling contact therewith.

7. A transmission chain comprising link plates having overlapping ends with aligning openings, a single pin member extending through said openings, said pin and: plates having cooperating ogee curves to form a joint.

8. A transmission chain comprising link plates having overlapping ends with aligning openings, a single pin member extending through said openings, said plates having ogee surfaces for cooperation with said pin to form a joint.

9. In a silent type chain, the combination of a plurality of overlapping links with registering openings, a single part pintle for the joints having convex and concave surfaces cooperating with like surfaces on the walls of the link openings, said cooperating surfaces being arranged to be in contact throughout a substantial portion of their area below the center line of the chain when the chain is under load between sprockets.

10. In a silent type chain, the combination of a plurality of links with registering openings, single part pintles for the joints having convex and concave surfaces coopcrating with like surfaces on the walls of the link openings, said cooperating surfaces being arranged to be in contact throughout a substantial portion of their area, below the center line of the chain when the chain is under load between sprockets. and means for holding the pintles in a predetermined relation to the respective links.

11. In a silent type chain, the combination of a plurality of overlapping linkswith registering openings, single part pintles for the joints, said pintles having convex and concave surfaces, convex and concave surfaces on the walls of the link openings cooperating with said pint-les and in contact therewith throughout a substantial portion of their area below the center line of the chain when the chain is under load between sprockets, whereby the elongation 

